Hand-Held Power Tool

ABSTRACT

A hand-held power tool, in particular a grinder, for simultaneously driving multiple grinding discs, includes at least one output shaft housing which surrounds multiple output shafts orthogonally to their output shaft axes, and a motor housing which at least substantially surrounds a motor orthogonally to the motor shaft axis. A cross-sectional surface of the motor housing running orthogonally to the motor shaft axis, in a narrower region of the motor housing, is less than 70% of the area of a cross-sectional surface of the output shaft housing running orthogonally to the output shaft axes, in a wider region of the output shaft housing, and/or one, in particular two, of the output shaft axes, are located outside the motor housing, preferably outside a concavely indented region of the hand grip, of the motor housing, and/or of the transition region between the hand grip and the motor housing.

The present invention relates to a hand-held power tool, in particular a grinder, for simultaneously driving a plurality of, preferably for driving three, in particular tiltable grinding disks that are driven in a rotating and/or oscillating and/or randomly circular manner.

PRIOR ART

Hand-held power tools of this kind are known for example from EP1466698.

DISCLOSURE OF THE INVENTION

A hand-held power tool having the features of claim 1 is proposed. Advantageous configurations, variants and developments of the invention can be found in the dependent claims.

The invention is based on a hand-held power tool, in particular a grinder, for simultaneously driving a plurality of, preferably for driving three, in particular tiltable grinding disks that are driven in a rotating and/or oscillating and/or randomly circular manner, having at least one output shaft housing which encloses at least three output shafts orthogonally to the output shaft axes, and a motor housing which substantially encloses the motor orthogonally to the motor shaft axis. It is proposed that a sectional area of the motor housing orthogonal to the motor shaft axis in an in particular constricted region of the motor housing amounts to less than 70%, in particular less than 65%, preferably less than 55%, relative to a sectional area of the output shaft housing orthogonal to the output shaft axes in an in particular extended region, in particular in the most extended region of the output shaft housing. The constricted region is located in particular in the region of a motor shaft or a region orthogonal to the motor shaft of the motor. The constricted region should be understood as being a narrowed region, in particular the region with the smallest sectional area. Advantageously, the visibility of the surface to be machined is increased. The hand-held power tool can be gripped more easily in different gripping positions. The in particular bar-shaped handle extends to above the grinding disks, with the result that the force application point is shifted to the middle of the plurality of, in particular three grinding disks. The grinder can optionally also be gripped in the constricted region and/or a palm can be placed on the output shaft housing. As a result, the force application point can be shifted very close to the surface to be ground. Multiple gripping positions, for example gripping the bar-shaped handle, placing the palm in particular from above on the motor housing, gripping the constricted region of the motor housing and/or placing the palm in the region of the output shaft housing.

It is proposed that the sectional area of the output shaft housing in a rear region of the hand-held power tool is covered to an extent of less than 75%, in particular less than 50%, preferably less than 25%, by the sectional area, projected along the motor shaft axis, of the motor housing. The rear region is in particular the region facing a bar-shaped handle of the hand-held power tool. By contrast, the front region faces in particular away from the handle. The region that corresponds to a preferred direction of movement of the hand-held power tool could also be at the front. The front can also be located where an output shaft comes to lie in a plane of mirror symmetry of the hand-held power tool. At the rear, the output shafts are spaced apart from the plane of mirror symmetry. Advantageously, the motor housing is arranged asymmetrically with respect to the output shaft housing. In particular, the motor is arranged asymmetrically with respect to the center of the output shaft housing, in particular shifted in the direction of the front, preferably shifted in an eccentric manner. Thus, the motor represents a counterweight to the in particular bar-shaped handle, preferably to the bar-shaped handle projecting toward the rear. The position of the center of gravity of the hand-held power tool can be positively affected as a result. In addition, the visibility of the rear grinding disk is improved. As a result, the grinder can be controlled or guided better. Undesired damage caused for example by elements vertically adjoining the surface to be ground can be avoided. Furthermore, a gripping capability can be achieved as a result, in particular a capability of gripping the bar-shaped handle over or between the output shaft housing and the bar-shaped handle. The force transmission or guiding of the hand-held power tool can take place as close as possible to the grinding disks.

It is proposed that the sectional area of the output shaft housing in a front region of the hand-held power tool is covered to an extent of more than 70%, in particular more than 90%, preferably entirely, by the sectional area, projected along the motor shaft axis, of the motor housing. As explained above, the location of the center of gravity, the force application point and/or the balancing of the motor weight and handle, which accommodates in particular a rechargeable battery, is positively affected as a result.

It is proposed that one, in particular two of the three output shaft axes, in particular the rear two output shaft axes of the hand-held power tool, are located outside the motor housing, in particular outside a or the constricted region of the motor housing. As a result, the motor housing has a very slim structure compared with the output shaft housing. The visibility of the material to be ground is increased. The hand-held power tool, in particular the bar-shaped handle, can be gripped better. An additional hand support surface is brought about on the output shaft housing, in particular in the region above the two rear output shafts.

It is proposed that one, in particular two of the three output shaft axes, in particular the rear two output shaft axes of the hand-held power tool, are located outside a handle, in particular a bar-shaped handle, preferably outside an indented region of the handle or an indented transitional region between the handle and motor housing. The force application point or the position of the center of gravity of the hand-held power tool is positively affected as a result. The handle and motor housing can be embodied in a very compact and/or narrow manner.

It is proposed that the third, in particular the front output shaft axis of the hand-held power tool is located inside the motor housing and/or inside the handle. In this way, an asymmetry between the motor housing and output shaft housing is created or eccentricity of the motor relative to the center of the output shaft housing is brought about. This affords the advantages as mentioned above.

An invention is also based on the fact that a grinding machine housing at least partially forms a handle with at least one housing shell element and with at least one further housing shell element connected to the housing shell element, characterized by at least one air vent, in particular a ventilation slot, formed at least partially in the region of a separating edge of the housing shell element and the further housing shell element. The air vent extends in particular over two regions that are arranged preferably at an angle, in particular an angle of between 90° and 120°, preferably between 100° and 105°, to one another. The length of the region regions differs in particular by no more than 50%, and preferably they are approximately the same length. The air vent can be arranged in particular on the right and left of the abovementioned motor housing. The air vents provide in particular an intake air and exhaust air capability, in particular of motor cooling air and exhaust air. Thus, it is possible for example for cooling air for the motor and/or the electronics of the hand-held power tool to enter through one air vent and to emerge through the other air vent. Furthermore, the air vent(s) can be intended to cool a user's hand and/or potentially evaporate sweat on the palm that arises when using the hand-held power tool. This takes place with a preferably with a region of the air vent that is arranged substantially horizontal and/or parallel to the handle orientation. The user-friendliness can thus be increased.

It is proposed that the housing shell element and the further housing shell element are connected together, in particular fixed together, in particular along an at least substantially entire contact line and/or face of the housing shell element and the further housing shell element, at least substantially without visible fastening elements. As a result, externally visible screw holes (for example for connecting conventional housing shells) are avoided. The appearance and ergonomics are enhanced.

The tool can be cleaned more easily. Bothersome holes in the region of the gripping faces are dispensed with.

It is proposed that the handle of the grinding machine housing is formed at least substantially without a separating edge at least on a side of the handle that faces and/or faces away from a tool side. The ergonomics are enhanced in this way, too. It is easier to assemble the hand-held power tool. Externally visible screw-fastening elements can be avoided. Air vents can be integrated into the in particular lateral separating edges.

Furthermore, a grinding machine housing having a motor housing portion and a bar-shaped handle housing portion is proposed, wherein the grinding machine housing has a concave recess, in particular an indentation, in a transitional region between the bar-shaped handle housing portion and the motor housing portion. As a result, an ergonomic contact face for a finger, in particular a thumb of the user can be created. The grinding machine housing can be gripped even better, the hold is improved and slipping made difficult. When the motor housing is gripped with the palm, too, the concave recess, in particular on both sides, serves as an ergonomic contact face for the thumb and/or index finger.

Furthermore, a hand-held power tool, in particular a grinder, having an abovementioned grinding machine housing is proposed.

DRAWINGS

The invention is explained in more detail in the following text by way of exemplary embodiments illustrated in the drawings, in which:

FIG. 1 shows a front view of the hand-held power tool;

FIG. 2 shows the hand-held power tool in a sectional illustration A-A;

FIG. 3 shows the hand-held power tool in a sectional illustration B-B;

FIG. 4 shows a side view of the hand-held power tool in a rest position;

FIG. 5 shows a side view of the hand-held power tool;

FIG. 6 shows a rear view of the hand-held power tool;

FIG. 7 shows a perspective view of the dust extraction hood;

FIG. 8 shows a side view of the system made up of the hand-held power tool and dust extraction hood;

FIGS. 9a-9d show four views of the hand-held power tool in shaded illustration;

FIG. 10 shows the sectional area and the sectional area ratio of a constricted and an extended region of the hand-held power tool;

FIG. 11 shows a perspective illustration of the hand-held power tool.

FIG. 1 shows a front view of the hand-held power tool in the form of a grinder 10. The grinder 10 is intended for the simultaneous driving of three grinding disks 12, 14, 16; one front grinding disk 12 and two rear grinding disks 14, 16. As a result of a universal-shaft-like or gimbaled mount (cf. FIG. 2) of the grinding disks 12, 14, 16, the latter are mounted in a pivotable or tiltable manner. They are driven in rotation and are highly suitable for grinding even curved surfaces. The grinder 10 is able to be activated via an actuating switch 18. An identification element 20 assigns this tool advantageously to a range of tools and/or a manufacturer.

FIG. 2 shows the hand-held power tool in the form of a grinder 10 in a sectional illustration A-A through the plane A (cf. FIG. 1). The front grinding disk 12 is arranged in front of a central gear axis 22. It is arranged opposite a handle 24 with regard to a central gear axis 22. The two rear grinding disks 14, 16, of which only the grinding disk 16 can be seen in this illustration, are arranged on a side of the central gear axis 22 facing the handle 24. The three grinding disks 12, 14, 16 are of identical construction and configured in an interchangeable manner. A motor 26 has a drive shaft 28. The motor 26, or the drive shaft 28 thereof, defines a motor shaft axis 30. Via a pinion 32, the motor 26 drives a central gear 34 that defines the central gear axis 22. The central gear 34 is driven by the pinion 32 via a spur gear 36. The central gear 34 has a toothing 38, with which it drives three output shafts 40, of which only the front one can be seen in the section A-A. These output shafts 40 in turn define output shaft axes 42. Each output shaft 40 is in turn intended to at least indirectly drive a respective grinding disk 12, 14, 16. The central gear 34 drives, via the toothing 38, three spur gears 44 (of which the spur gear 44 driving the grinding disk 12 can be seen in the section and the spur gear 44 driving the grinding disk 16 can be seen in the side view). The front spur gear 44 drives the output shaft 40; the drive mechanism can be assigned analogously to all the spur gears 44 driving the grinding disks 12, 14, 16. The output shaft 40 is mounted here for example via at least one grooved ball bearing 46 in one housing part 60. A plain bearing 48 additionally supports the output shaft 40 in a further housing part 62. The two housing parts 60, 62 form an output shaft housing 202. The output shaft housing 202 forms, together with a motor housing 200, which substantially encloses the motor 26, a main housing 64, which accommodates at least the motor 26, the central gear 34 and the drive and output shafts 28, 40. The output shaft 40 engages, via a catch 50 in coupling means 52 of the grinding disk 12. The grinding disk 12 can be clipped into a grinding disk receptacle 56 by means of latching hooks 54. The grinding disk receptacle 56 is arranged in the region of an opening 100 in the housing part 60. Through the opening 100, the coupling means 52 of the grinding disk 12 and the latching hooks 54 can be plugged into the grinding disk receptacle 56 and onto the catch 50, respectively. The grinding disk receptacle 56, in addition to allowing the low-friction rotational mounting of the grinding disk 12 (in this case with a grooved ball bearing 58), also allows pivoting (in this case by way of a spherical plain bearing in a spherical receptacle in the housing part 60). The universal-shaft-like drive allows the grinding disk to be tilted with respect to the housing part 60 or relative to the grinder 10. The central gear 34 drives the grinding disks 12, 14, 16 forcibly in rotation. In principle, however, it is also possible for the grinding disks 12 to be driven in oscillation or in a randomly circular manner, for example by way of output shafts 40 that are accommodated eccentrically in the spur gear 44 and drive the grinding disks 12, 14, 16 in rotation in a positively coupled or random manner, or an eccentric which generates an oscillating movement by restricting the degrees of freedom of the grinding disk and/or of the output shaft—or the like (not illustrated in more detail here).

The drive shaft 28 or the motor shaft axis 30 is arranged eccentrically with respect to the central gear 34 or to the central gear axis 22, respectively. It is arranged between the front output shaft axis 42 and the central gear axis 22. The two axes 22, 30 are intersected by the plane A or come to lie therein. The motor 26 has been shifted in the direction of the front grinding disk 12 or the grinding disk receptacle 56 thereof. The motor 26 or the motor shaft axis 30 thereof is arranged opposite the handle 24 with regard to the central gear axis 22. The handle 24 is likewise intersected centrally by the plane A, and ideally divided in a mirror symmetric manner. The motor shaft axis 30, the central gear axis 22 and the output shaft axes 42 are oriented parallel to one another. The handle axis 66, or the central axis 86 or longitudinal axis 84 of the in particular bar-shaped handle 24 is arranged transversely to the central gear axis 22. The angle α is around 45-135°, in the present exemplary embodiment around 100°. The handle 24 projects from the main housing 64. The plane A or the section plane A-A is, to a certain extent, also defined by the handle axis 66 and the central gear axis 22. The handle 24 is bar-shaped, substantially round or oval or the like. It is formed by the handle housing 68, which can be formed at least partially in one piece with the main housing 64. The handle 24 is intended to accommodate a rechargeable battery 70. The latter can be integrated permanently or be in the form of an exchangeable rechargeable battery 70. In the present exemplary embodiment, it is in the form of an exchangeable slide-in rechargeable battery 72. It is slid into the free end 74 of the handle 24 and is connected to the handle housing 68 in a releasable manner via latching elements that are not illustrated here. Optionally, a rotational speed of the motor 26 can be set via a setting dial 76. Furthermore, the handle 24 and the main housing 64 are shaped in an ergonomic manner. The concave indent 78 at the transition from the handle 24 to the main housing 64 serves for intuitively gripping with the index finger. This region can also be covered with a soft grip 80. Of course, it is also possible for other regions of the hand-held power tool to be covered with specifically haptic and/or tactile materials. However, the top side 82 of the main housing 64 is also intended for a hand in particular the palm to rest on, in order to guide the hand-held power tool with two hands or one hand, simply by gripping the main housing 64.

FIG. 3 shows the grinder from FIG. 1 in a sectional illustration B-B in the plane (B). The drive shaft 28 drives the central gear 34 via the pinion 32. The motor shaft axis 30 and thus the motor 26 is arranged eccentrically with respect to the central gear 34. Specifically, it has been shifted in the direction of a front side 90 of the grinder 10. The central gear axis 22, the motor shaft axis 30 and the output shaft axis 42 of the front output shaft come to lie in the plane A. The plane B is defined orthogonally to this plane A. The output shafts 40 arranged mirror-symmetrically to the plane A come to lie in the plane B. The central gear axis 22 is arranged in the center of a regular triangle 92, in the corners of which the three output shaft axes 42 are arranged. Via the central gear 34, the three spur gears are driven in rotation. The spur gears 44 in turn drive the output shafts 40, which at least indirectly drive the grinding disks 12, 14, 16 or grinding disk receptacles 56 (cf. FIG. 2). Furthermore, parts of the main housing 64, or of the housing part 60 and the further housing part 62, which keep the drive and output elements of the grinder 10 in position, are illustrated.

FIG. 4 shows the grinder 10 in a rest position on a support surface 94, for example a workpiece to be machined. The grinder 10 rests on three points, specifically on a free end 96 of the slide-in rechargeable battery 70 (alternatively, it could also rest on the free end 74 of the handle 24, in particular in the case of a rechargeable battery 70 permanently installed in the handle 24) and on the rim 98 of the rear grinding disks 14, 16, in particular the two rims 98, facing the free end 74, 96 of the handle 24 or slide-in rechargeable battery 72, of the grinding disks 14, 16 (wherein only the grinding disk 14 is visible since it conceals the grinding disk 16). In principle, the same reference signs are allocated to identical components in the various figures, but they are not necessarily explained again for each figure.

FIG. 5 shows a side view of the hand-held power tool or a grinder 10. The housing part 60 has three grinding disk receptacle regions 102, of which only two can be seen in FIG. 5. A grinding disk receptacle region 102 is defined as being the region of the housing part 60 that supports the grinding disk receptacle 56 and the components thereof, for example bearings. For example, this is the region with the envelope circle diameter 104 around the grinding disk receptacle regions 102. In the present exemplary embodiment, this region is offset from an in particular immediately surrounding housing region 106 of the housing part 60, in the direction of the grinding plane 112 (for accommodating the bearings, improved accessibility and/or for improving the freedom of movement of the grinding disks 12, 14, 16 for example during tilting/pivoting). Put another way, the surrounding housing region(s) 106 is/are set back with respect to the grinding disk receptacle region(s) 102. This set-back should not be understood as being a cavity 108 within the meaning of the invention. The grinding disk receptacle regions 102 each have openings 100, through which the removable grinding disks 12, 14, 16 can be connected to the grinder 10. Thus, the coupling means and/or latching hooks 54 can be connected to the output shafts 40 and/or grinding disk receptacles 56 (cf. sectional illustration in FIG. 2). Alternatively, however, the grinding disk receptacles 56 or the output shafts 40 can also project through the grinding disk receptacle regions 102. If only output shafts 40 project through the housing part, be this because the grinding disks 12, 14, 16 are received outside the housing part 60 of the hand-held power tool, or because the grinding disks 12, 14, 16 are connected permanently to the output shafts 40, the grinding disk receptacle region 102 can also be understood as being only the region that represents the opening 100; or the region that mounts the output shafts 40 in the housing part 60 of the hand-held power tool.

Between two adjacent grinding disk receptacle regions 102 or the openings 100 (so to speak in the intermediate space 122), the housing part 60 has an air duct 120. The latter is formed by a cavity 108. In the region of the air duct 120 or of the cavity 108, the distance 110 between the housing part 60 and a grinding plane 112 is increased, in particular increased compared with the distance 111 of the housing region 106 from the grinding plane 112. The cavity 108 is accordingly set back with respect to the housing region 106. The cavity 108 has a concave shape 118. It extends in the direction of the center of the housing part 60, or becomes narrower in the circumferential direction. In addition, a dimension of the cavity decreases in this direction. The housing part is thus indented or recessed in the direction away from the grinding plane 112. Starting from a central region 114 of the housing part 60, in particular a central region 114 at the center between the grinding disks 12, 14, 16 or in the region of the central gear axis 22 intersecting the housing part 60, the distance 110 between the housing part 60 and grinding plane 112 increases outwardly in the radial direction, i.e. in the direction of the rim 116 of the housing part 60, along the air duct, or the cavity 108. The cavity 108 is thus larger in the outer region of the housing part 60 than in a central region. The cavity 108 serves for better air guidance. The cavity 108 forms at least a part of an air duct 120, in particular for dust extraction.

Similarly to the cavity 108 between the grinding disks 12, (front and rear grinding disk) or the associated grinding disk receptacle regions 102, a cavity 108 is also provided between the rear grinding disks 14, 16 or the associated grinding disk receptacle regions 102 (cf. FIG. 6). It is also apparent from FIG. 6, which shows a rear view of this cavity, that the cavity or the distance 110 increases from the central region 114 of the housing part 60 to the rim 116 of the housing part 60 or radially outwardly from the center. The rear cavity 108 is constructed in a mirror-symmetric manner to the plane A (cf. also section A-A according to FIG. 2). The cavity 108 also allows contact-free tilting 124 of the grinding disks 12, 14, 16 relative to the housing part 60. Thus, for example during operation of the grinder 10, a rim of the grinding disk 12, 14, 16 does not rub against the housing part 10. The three cavities 108 between the grinding disks 12, 14, 16 or the grinding disk receptacles 56 are arranged in a manner offset from one another in each case by 120° starting from the center.

They are each mirror-symmetric to the angle bisector of the regular triangle.

FIGS. 5 and 6 also show a housing separating edge 126. The housing separating edge 126 is arranged between the housing part 60 and the further housing part 62. The two housing parts 60, 62 are part of the output shaft housing 202 or of the main housing 64. The housing separating edge 126 represents in particular a housing parting line 130. The housing separating edge 126 or the housing parting line 130 is formed by the assembled housing shells of the hand-held power tool or grinder 10. It forms a set-back in the housing surface. It encircles the output shaft housing 202. It represents a form-fitting element 132, in particular a latching groove 134, serves for receiving a corresponding form-fitting element 136 of a dust extraction hood 138 (cf. FIG. 7), preferably a latching protrusion 140 of a dust extraction hood 138. The form-fitting element 132, rather than a groove or recess, could in principle also be in the form of a protrusion or male form-fitting element. Similarly, rather than a male form-fitting element, a female form-fitting element may be provided on the dust extraction hood 138. Furthermore, the cavity 108 in the housing part 60 serves as a further form-fitting element 142, in particular as a stop element 144 for a further corresponding form-fitting element 146 on the dust extraction hood 138. When the dust extraction hood 138 is plugged, as intended, from the grinding disk plane 112 onto the output shaft housing 202 or is fitted over the housing part 60, the form-fitting element(s) 146 serve(s) as a stop or stopper. Thus, the dust extraction hood 138 is not pushed too far onto the output shaft housing 202. As soon as the form-fitting elements 146 come into contact, the form-fitting elements 136 also engage in their intended position or in the corresponding form-fitting elements 132.

FIG. 7 shows a perspective view of the dust extraction hood 138. A removable dust-extraction hood 138 for a hand-held power tool, in particular for the grinder 10, is, in particular wherein the hand-held power tool is configured to drive a plurality of, in particular tiltably mounted, grinding disks 12, 14, 16 that are drivable in rotation and/or oscillation and/or in a randomly circular manner. The dust extraction hood 138 has a connecting piece 148 for connecting to a dust extraction device (not illustrated here)—typically a mobile or stationary vacuum cleaner or dust extraction device. The connecting piece 148 projects towards the outside 149 of the dust extraction hood 138. The dust extraction hood 138 has an extraction opening 150 starting from the connecting piece 148, said extraction opening 150 being open toward the inside 152 of the dust extraction hood 138. The dust extraction hood 138 has a substantially triangular geometry, in particular a substantially regular triangular geometry. The term “substantially” should be understood here as meaning that the corners 154 of the “triangle”, as illustrated in FIG. 7, can be rounded. In addition, the legs 156 can also deviate to a certain extent from a straight form, for example be slightly arcuate or the like.

In the region of the extraction opening 150, the dust extraction hood 138 has an extension 158. The latter serves to avoid a transverse airflow, in particular from beneath 184 (cf. FIG. 8) the extension 158, i.e. beneath that side of the extension 158 that faces away from the extraction opening 150. The extension 158 projects into the inside 152 of the dust extraction hood 138. Starting from the extraction opening 150, the extension 158 has a main extension direction 160 into the inside 152 of the dust extraction hood 138. Furthermore, the extension 158 has at least one, in particular two walls 162. The latter serve(s) to reduce transverse airflow, in particular to reduce transverse airflow from beneath 184 the dust extraction hood 138 and/or from the side 164 within the dust extraction hood 138. The extension 158 and/or the wall 162 can, however, also be open at least partially at the side 166, 168, in particular to allow transverse airflow in at least this region 170, 172. The extension 158 forms a part of an air duct 159. In particular, the part of the air duct 120 and the other part of the air duct 159 together form an air duct 120, 159.

The dust extraction hood 138, or the frame 174 of the dust extraction hood 138, is flexible, in particular transversely to the underside or top side of the dust extraction hood 138 or in the direction of the inside 152 or the outside 149 of the dust extraction hood 138. This allows spring-elastic preloading and/or pressing of the dust extraction hood 138 against the hand-held power tool, in particular the grinder 10, or the housing thereof. As a result, a tool-free and/or secure and/or low-gap connection to the grinder 10 can be established.

The frame 174 or the dust extraction hood 138 narrows from bottom to top. In the region of the form-fitting elements 136, for connecting to the form-fitting elements 142 of the hand-held power tool, the frame 174 or the dust extraction hood 138 is narrowed. This ensures that an upper rim 186 of the frame 174 or of the dust extraction hood 138 can bear as far as possible without a gap against the housing of the hand-held power tool. The preloading force of the dust extraction hood 138 in this region can thus act particularly efficiently.

Furthermore, the dust extraction hood 138 can be in the form of a spacer and/or impact protector for the hand-held power tool or grinder (cf. also FIG. 8). Rather than the housing of the grinder 10, the frame 174, or the rounded corners 154 and/or legs 156 serve(s) as impact protector. The dust extraction hood 138 also has a gripping contour 176. The gripping contour 176 represents a slight elevation on the leg 156 or the frame 174. The friction between finger and dust extraction hood 138 when the dust extraction hood 138 is pushed onto or pulled off the grinder 10 is improved as a result. In addition, the gripping contour 176 resembles the silhouette contour 178 at least of a region of the hand-held power tool or grinder (cf. FIGS. 5 and 6). The silhouette contour is formed in this case by the contour of the rim 116 of the housing part 60, in particular in the region of the cavity 108, in particular when the rim 116 or the grinder 10 is viewed from the side.

FIG. 8 illustrates the system made up of the hand-held power tool or grinder 10 and the connected or plugged-on dust extraction hood 138. In addition to the above-described components, the dust extraction hood 138 or the hand-held power tool or grinder 10 has an in particular elastic connecting element 179, in particular an elastic band 180, preferably a rubber-elastic band 180, for connecting the connecting piece 148 or a connecting-piece adapter 182 and the grinder 10. The elastic band 180 is tensioned in particular between a free end 74, 96 of the handle 24 or rechargeable battery 70, 72 of the grinder and the connecting piece 148 or connecting-piece adapter 182. Preferably, the elastic band is fastened captively to the connecting piece 148, connecting-piece adapter 182 or handle 24. In this case for example by being adhesively bonded to or injection molded on the connecting-piece adapter. Alternatively, the band can also be releasable on one side, such that, in the open state, it can be attached to or wrapped around the respectively other component and be fixed again—for example by way of a snap fastener, a locking mechanism or the like.

FIG. 9, subfigures a-d, shows the hand-held power tool or grinder 10 from the preceding figures in a shaded illustration in order to also make curves visible. Subfigure 9 a shows the grinder 10 in a side view, subfigure 9 b shows it in a rear view, subfigure 9 c in a perspective view and subfigure 9 d in a plan view. The grinder 10 is for the simultaneous driving of three, in particular tiltable, grinding disks 12, 14, 16 that are driven in rotation and/or oscillation and/or in a randomly circular manner, having at least one output shaft housing 202, which substantially encloses three output shafts 40 (not illustrated here, cf. in particular FIG. 2) orthogonally to the output shaft axes 42, 202, 204, 206, and a motor housing 200 which substantially encloses the motor 26 orthogonally to the motor shaft axis 30. The grinder 10 has a handle 24. The front output shaft axis 42, 204 can be distinguished better from the rear output shaft axes 42, 206, 208 by the additional reference signs. The output shaft housing 202 encloses the three output shafts 40 at least substantially orthogonally to the output shaft axes 42. The motor housing 200 encloses the motor 26 at least substantially orthogonally to the motor shaft axis 30.

A sectional area 210 of the motor housing 200 orthogonal to the motor shaft axis 30 in a constricted region 212 of the motor housing 200 amounts to less than 70%, in particular less than 65%, preferably less than 55%, relative to a sectional area 214 of the output shaft housing 202 orthogonal to the output shaft axes 42 in an extended of the output shaft housing 202, in particular in the most extended region 216 of the output shaft housing 202. In the illustrated FIG. 10, it amounts to around 52%. The extended region 216 should be understood as being in particular the region with the greatest sectional area 214 of the output shaft housing 202. Thus, in this region 216, an extent for example the length 218 of the circumferential distance or length 215 around the output shaft housing 202, is at a maximum. Furthermore, in the side view, rear view and plane view in subfigures 9 a-c, a length and a width of the motor housing 200 in the constricted region 212 and of the output shaft housing 202 in the extended region 216 are provided with the following reference signs: output shaft housing 202: length 218, width 220; motor housing: length 222, width 224. In terms of ratio, the extended region 216 of the output shaft housing 202 with respect to the constricted region 212 of the motor housing 200 is around 30% longer and around 65% wider. The sectional area ratio of the extended region 216 of the output shaft housing 202 with respect to the constricted region 212 of the motor housing 200 also amounts to around 190% (cf. FIG. 10).

The sectional area ratio of certain regions is also apparent from FIG. 10. The sectional area 214 of the output shaft housing 202 in a rear region 226 of the hand-held power tool or grinder 10 is covered to an extent of less than 75%, in particular less than 50%, preferably less than 25%, by the sectional area 210, projected along the motor shaft axis 30, of the motor housing 200, in particular in the constricted region 212. Similarly, the grinding area 232 of grinding disks 14, 16 applied to the rear of the grinder 10 is covered to an extent of less than 75%, in particular less than 50%, preferably less than 25%, by the sectional area 210, projected along the motor shaft axis 30, of the motor housing 200, in particular in the constricted region 212. In a front region 228 of the hand-held power tool, the sectional area 210, projected along the motor shaft axis 30, of the motor housing 200, in particular also in the constricted region 212, covers the sectional area 214 of the output shaft housing 202 to an extent of more than 70%, in particular more than 90%, preferably entirely. Similarly, the grinding area 234 of a grinding disk 12 applied at the front of the grinder 10 is covered to an extent of more than 70%, in particular more than 90%, preferably entirely, by the sectional area 210, projected along the motor shaft axis 30, of the motor housing 200, in particular also in the constricted region 212.

Furthermore, a circumferential length 211 of the motor housing 200 orthogonal to the motor shaft axis 30 or the output shaft axes 42 in an in particular constricted region 212 of the motor housing 200 relative to a circumferential length 215 of the output shaft housing 202 orthogonal to the output shaft axes 42, 204, 206, 208 in an in particular extended region 216 of the output shaft housing 202 can be seen in FIG. 10. It amounts to less than 80%, in this case approximately 70%. Put another way, the circumferential length 215 of the output shaft housing 202 compared with the circumferential length 211 of the motor housing 200 in the constricted region 212 amounts to around 145%.

Furthermore, one, in particular two of the three output shaft axes 42, in particular the rear two output shaft axes 206, 208 of the hand-held power tool, is/are located outside the motor housing 200, in particular outside the constricted region 212 of the motor housing 200. These output shaft axes 206, 208 thus at least do not intersect the motor housing 200 in the constricted region 212, and in particular do not intersect the motor housing 200 anywhere. Furthermore, in particular one, preferably two of the three output shaft axes 204, 206, 208, in particular the rear two output shaft axes 206, 208 of the hand-held power tool or grinder 10, are located outside the handle 24, in particular outside the bar-shaped handle 24. They are also located outside an indented region 230 or a concave recess in the handle 24 and/or motor housing 200 or outside an indented transitional region 276 between the handle 24 and motor housing 200. The front output shaft axis 204 of the hand-held power tool or grinder 10 is located inside the motor housing 200 and/or inside a motor housing handle 236—and therefore intersects it/them.

It is also apparent from the side view according to FIG. 9a that the ratio of the height 238, 240 of the hand-held power tool in the direction of the output shaft axes 42, 204, 206, 208, in particular a height 238 of a motor and output shaft housing 200, 202, to the length 242 of a substantially bar-shaped handle 24, in particular a length 242 of a bar-shaped handle 24 projecting substantially orthogonally with respect to the motor housing 200 or the drive and output shaft axis 30, 204, deviates by less than 50%, in particular by less than 75%, preferably by less than 85%, in particular is more or less identical. A bar-shaped handle projecting substantially orthogonally with respect to the drive and output shaft axis/axes 30, 204 should be understood here as being in an angular range from 60°-120°, in particular from 75°-105°, preferably 90° with regard to the drive and output shaft axis/axes 30, 204, 206, 208. Advantageously, a very compact hand-held power tool can be provided as a result. The center of gravity S thus moves as close as possible to the grinding disks 12, 14, 16. Furthermore, a ratio of a total length 244 of the hand-held power tool orthogonal to at least one drive or output shaft axis 30, 42, 204, 206, 208, in particular from an end of the motor housing 200 to an end of the handle 24 projecting in a bar-shaped manner, relative to a height 238, 240 of the hand-held power tool in at least one direction of the drive or output shaft axis 30, 42, 204, 206, 208, in particular from a grinding disk plane 112 to the end of the handle 24 or motor housing 200, is greater than 10%, in particular greater than 25%, preferably around 40% greater.

Furthermore, the weight of the rechargeable battery 72 relative to the components of the power train, in particular comprising the motor 26, the pinion 32, the central gear 34, the output shafts 40 and spur gears 44, amounts to around 10-50% more, in particular 30-40% more. As a result, the position of the center of gravity S can be positively affected. A volume of the motor and output shaft housing 200, 202 compared with the bar-shaped handle housing 68 amounts to around 20-70% more, in particular around 50% more.

Furthermore, a grinding machine housing 250 having at least one housing shell element 252 and having at least one further housing shell element 254 connected to the housing shell 252, which at least partially form a handle 24, 258, can be seen in the side view and the perspective view according to FIGS. 9a, d and FIG. 11. The grinding machine housing 250 is characterized by at least one air vent 262, in particular a ventilation slot, formed at least partially in the region of a separating edge 260 of the housing shell element 252 and the further housing shell element 254. The air vent 262 extends advantageously over two regions 264, 266 that are arranged at an angle 268, in particular an angle 268 (cf. FIG. 10, side view) of between 90° and 120°, preferably between 100° and 105° to one another. Advantageously, the angle is based on the orientation of the bar-shaped handle with respect to the motor housing. The air vent regions are advantageously oriented parallel to the main extent thereof. Advantageously, the air vent 262, in particular the one of the portion 266 in the region of the handle 258, is intended to blow air around a user's hand, in particular to cool, heat and/or dry it.

The housing shell element 252 and the further housing shell element 254 are connected together, in particular fixed together, in particular along an at least substantially entire contact line and/or face of the housing shell element 252 and the further housing shell element 254, at least substantially without visible fastening elements. Furthermore, the handle 24, 258 is formed at least substantially without a separating edge on a side of the handle 24, 258 that faces and/or faces away from a grinding disk 12, 14, 16 or tool side.

Furthermore, the grinding machine housing 250 has a motor housing portion 270 and a bar-shaped handle housing portion 272, wherein the grinding machine housing 250 has a concave recess 278 or an indentation (cf. FIG. 10) in a transitional region 276 between the bar-shaped handle housing portion 272 and the motor housing portion 270. Said recess or indentation serves as an ergonomic contact face for a finger, in particular a thumb of the user. The indentation is readily apparent in particular from the side view in FIG. 9a . The shading indicates the curved regions. Preferably, the air vent(s) 262 is/are able to be formed by an offset of a housing edge of the housing shell element 252 and of the further housing shell element 254. 

1-12. (canceled)
 13. A hand-held power tool for simultaneously driving a plurality of grinding disks, comprising: a plurality of output shafts defining output shaft axes; at least one output shaft housing enclosing the plurality of output shafts orthogonally to the output shaft axes; a motor having a motor shaft axis; and a motor housing which at least substantially encloses the motor orthogonally to the motor shaft axis, wherein a first sectional area of the motor housing orthogonal to the motor shaft axis in a constricted region of the motor housing amounts to less than 70% relative to a second sectional area of the output shaft housing orthogonal to the output shaft axes in an extended region of the output shaft housing.
 14. The hand-held power tool as claimed in claim 13, wherein a rear region of the second sectional area of the output shaft housing is covered to an extent of less than 75% by the first sectional area of the motor housing projected along the motor shaft axis.
 15. The hand-held power tool as claimed in claim 14, wherein the rear region is in a region of at least one rear output shaft axis of the output shaft axes, and the extent to which the rear region of the second sectional area is covered by the first sectional area is less than 25%.
 16. The hand-held power tool as claimed in claim 13, wherein a front region of the second sectional area of the output shaft housing is covered to an extent of more than 70% by the first sectional area of the motor housing projected along the motor shaft axis.
 17. The hand-held power tool as claimed in claim 16, wherein the front region is in a region of a front output shaft axis of the output shaft axes, and the front region is entirely covered by the first sectional area.
 18. The hand-held power tool as claimed in claim 13, wherein a circumferential length of the motor housing orthogonal to the motor shaft axis in the constricted region of the motor housing is less than 80% of a circumferential length of the output shaft housing orthogonal to the output shaft axes in the extended region of the output shaft housing.
 19. The hand-held power tool as claimed in claim 18, wherein the circumferential length of the motor housing orthogonal to the motor shaft axis in the constricted region is less than 70% of the circumferential length of the output shaft housing orthogonal to the output shaft axes in the extended region of the output shaft housing.
 20. The hand-held power tool as claimed in claim 13, wherein at least one of the output shaft axes is located outside the motor housing.
 21. The hand-held power tool as claimed in claim 20, wherein the at least one of the output shaft axes located outside the motor housing includes two rear output shaft axes that are located outside the constricted region of the motor housing.
 22. The hand-held power tool as claimed in claim 20, wherein the at least one of the output shaft axes located outside the motor housing is located outside a handle of the hand-held power tool, outside the motor housing, and/or outside a transitional region between the handle and motor housing.
 23. The hand-held power tool as claimed in claim 22, wherein another one of the output shaft axes is located inside the motor housing and/or inside the handle.
 24. The hand-held power tool as claimed in claim 13, wherein a height of the hand-held power tool in a direction of the output shaft axes deviates by less than 50% from a length of a substantially bar-shaped handle.
 25. The hand-held power tool as claimed in claim 13, wherein a total length of the hand-held power tool orthogonally to the drive axis or the output shaft axes is at least 10% greater than a height of the hand-held power tool in at least one direction of the drive axis or output shaft axes.
 26. The hand-held power tool as claimed in claim 13, wherein the first sectional area is less than 55% of the second sectional area.
 27. The hand-held power tool as claimed in claim 13, wherein the hand-held power tool is a grinder configured to drive the plurality of grinding disks in a rotating and/or oscillating and/or randomly circular manner.
 28. The hand-held power tool as claimed in claim 13, further comprising: a grinding machine housing comprising: at least one housing shell element; and at least one further housing shell element connected to the housing shell element, the at least one housing shell element and the at least one further housing shell element at least partially forming a handle, wherein at least one air vent is defined at least partially in a region of a separating edge of the at least one housing shell element and the at least one further housing shell element such that the air vent extends over two regions that are arranged at an angle of between 90° and 120° relative to one another.
 29. A grinding machine housing comprising: at least one housing shell element; and at least one further housing shell element connected to the housing shell element, the at least one housing shell element and the at least one further housing shell element at least partially forming a handle, wherein at least one air vent is defined at least partially in a region of a separating edge of the at least one housing shell element and the at least one further housing shell element such that the air vent extends over two regions that are arranged at an angle of between 90° and 120° relative to one another.
 30. The grinding machine housing as claimed in claim 29, wherein the housing shell element and the further housing shell element are fixed together along an at least substantially entire contact line and/or face of the at least one housing shell element and the at least one further housing shell element, at least substantially without visible fastening elements.
 31. The grinding machine housing as claimed in claim 29, wherein the handle is formed at least substantially without a separating edge at least on a side of the handle that faces toward and/or faces away from a tool side.
 32. A grinding machine housing comprising: a motor housing portion and a bar-shaped handle housing portion, wherein the grinding machine housing has a concave recess in a transitional region between the bar-shaped handle housing portion and the motor housing portion such that said concave recess serves as an ergonomic contact face for a finger or a thumb of a user. 